Growth or Decay? Rate?
Exponential Growth
Exponential Decay
4. Compound Interest
100

y=1,200(1+0.3)t

Growth; 30%

100

The first year of a charity walk event had an attendance of 500. The attendance y increased by 5% each year. How many people will attend in the 10th year? Round your answer to the nearest person. 

y=500(1.05)t; 814 people

100

The yearly profits of a company is $25,000. The profits have been decreasing by 6% per year. What will be the profits in 8 years? Round your answer to the nearest dollar.

y=25,000(0.94)t; $15,239

100

Jasmine deposits $520 into a savings account that has a 3.5% interest rate compounded monthly. What will be the balance of Jasmine’s savings account after two years? Round to the nearest cent.

$557.65

200

y=55(1-0.02)t

Decay; 2%

200

The population of a small town was 3600 in 2005. The population increases by 4% annually. What will the population be in 2025? Round your answer to the nearest person. 

y=3,600(1.04)t; 7,888 people

200

You bought $2,000 worth of stocks in 2012. The value of the stocks has been decreasing by 10% each year. What will your stock be worth in 2017? Round your answer to the nearest cent.

y=2,000(0.9)t; $1180.98

200

If you deposit $6,500 into an account paying 8% annual interest compounded monthly, how much money will be in the account after 7 years? Round to the nearest cent.

$11,358.24

300

y=100(1.25)t

Growth; 25%

300

Your starting salary at a new company is $34,000 and it increases by 2.5% each year. In how many years will your salary be about $38,400? Round your answer to the nearest year. 

y=34,000(1.025)t; 5 years

300

Your car cost $42,500 when you purchased it in 2015. The value of the car decreases by 15% annually. In what year will your car be worth $13,625? Round your answer to the nearest year.

y=42,500(0.85)t; 2022

300

What is the continuous compound formula? What is the compound interest formula?

A=Pert; A=P(1+(r/n))nt

400

y=5,575(0.65)t

Decay; 35%

400

In 2010 an item cost $9.00. The price increased by 1.5% each year. In what year will it costs $12.12? Round your answer to the nearest year.

y=9(1.015)t; 2030

400

A piece of land was purchased for $65,000. The value of the land has slowly been decreasing by 1% annually. In how many years will it be worth $53,164? Round up to the nearest whole year. 

y=65,000(0.99)t; 20 years

400

Tina invested $3000 in a bank that pays an annual interest rate of 7% compounded continuously. What is the amount she can get after 5 years from the bank? Round your answer to the nearest integer.

$4,257

500

y=14,000(0.95)t

Decay; 5%

500

In China in 1980, there were 1,100 pandas. The population has increased by 4% annually. In what year were there 1,500 pandas? Round your answer to the nearest year.

y=1,100(1.04)t; 1988 

500

A new soccer ball dropped onto the concrete from a height of 4 feet rebounds about 1/3 the height on each successive bounce. After how many bounces would the soccer ball rebound less than 1 foot? Round up to the nearest whole number.

y=48(1/3)t; 2 bounces

500

If Lex deposited $1780.80 into an account paying 6.8% annual interest compounded annually, how much money will be in the account after 6 years? Round to the nearest cent.

$2,642.67